precision lowp float;

varying vec2 vUv;
varying float vElevation;

void main() {
    //gl_FragColor=vec4(vUv,0.0,1.0);
    float height = vElevation * 2.0 + 0.4;//0-0.8
    gl_FragColor = vec4(1.0 * height, 0, 0, 1);
}